Tool boxes and storage containers that sit on the floor generally serve one purpose. They hold what needs to be stored and serve no other purpose. If sufficiently light, many times, users generally pick up the tool box or storage box and place it on a shelf or short table where they can look through it more easily. They lift the storage box or tool box so that it is placed at a more comfortable height to search for the stored item needed. Basically, the user is placing the box in a more ergonomic position where he or she does not have to bend over or kneel down to search the contents of the box. When the box is too heavy, the user has to bend over the box in a less comfortable position to search the contents. In the alternative, the user will kneel or sit beside the box to search the contents. This may be more comfortable than bending over the box, but still less ergonomic than if the box could be placed at a proper height to gain access to the contents.
In addition, tool boxes or storage boxes are typically single purpose items. The primary purpose is the only purpose. Namely, they store items, such as tools and have no other purpose.